Non-conducting lining or covering.



UNITED STATES PATENT FFICE.

GEORGE KELLY, OF MINERAL POINT, WISCONSIN.

NON-CONDUCTING LINING OR COVERING.

SPECIFICATION forming part of Letters Patent N 0. 665,229, dated January 1, 1901.

Application fil d October 18, 1898. Renewed November 15, 1900. serial No. 36,575. (No specimens.)

To all whom, it may concern.-

Be it known that I, GEORGE KELLY, a citizen of the United States, residing at Mineral Point, in the county of Iowa and State of Wisconsin, have invented certain new and useful Improvements in Non-Conducting Linings or Coverings; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to the manufacture of an improved non-conducting lining for refrigerator-cars,cold-storage apartments, heated surfaces, and the like; and the object is to provide a cheap, effective, and durable lining of this character.

To this end the invention consists in a lining or covering formed of the purified cellulose fiber of the flax and a suitable filler, as will be hereinafter more fully described, and particularly pointed out in the claims.

The percentage, by weight, of the ingredients found by practical tests to be the best for the above uses is one of fiax fiber to, two

of disintegrated vegetable tissue; but this proportion may be varied somewhat, according to'the uses to which the material is to be put, without departing from the spirit of my invention.

In preparing my improved lining I first take the above-named purified cellulose fiber and by means of suitable-and usual devices for a like purpose treat it until it is finely separated. The chemical treatment preferred, to which the cellulose fiber is subjected, is a chemical treatment of a combination under certain ratios or proportions of caustic soda and sulfur in solution, which naturally wets the fiber or any material into the composition of which it enters. The flax fiber and the vegetable tissue, such as woodpulp, are first made wet and then mixed together before being treated chemically, as above stated, and when applied as a covering to steam-pipes or as a lining for refrigerators or cold-storage compartments or apartments forms a perfect non-conductor of heat or cold to and from the article which has been lined or covered with said non-conducting material. I then add the filler, which is preferably a partially-disintegrated vegetable tissue, in which the lignins and resins are present, after which the mass is drained, molded, pressed into any desired shape, and dried. The resulting material is light, porous, very strong and flexible, and is very desirable for the above uses, and is one that overcomes many, if not all, of the difficulties of and objections to other materials used for the above purposes, inasmuch as it is selfsustaining and odorless.

When the material is to be used as a nonconducting covering for insulating heated surfaces, I prefer to substitute as a filler some fireproof material in place of the disintegrated vegetable tissue, as per the above percentage of weights, or the material itself may be rendered fireproof or waterproof by proper treatment with any recognized agent employed for such purposes.

Owing to the peculiarities of the cellulose fiber derived from the flax, it is evident that a material of which this is a component part will have a greater strength and resiliency with less weight than any of the wood or straw pulp mixtures on account of the greater length and strength of its fiber and the filaments composing them, the stalks of the flax being out into appropriate lengths for the purpose, the fiber maintaining its length and strength in said cuts of said stalks thus previouslyprepared. Thehigh non-conductivity of this fiber (or any material into the composition of which it enters) is a fact sequent upon its structure and treatment. The fiber of the flax is cylindrical and hollow, and the chemical treatment to which it is previously subjected preserves its strength and structure, thoroughly removes the lignose, lignin, lignone, and lignireose, as well as the gums and carbohydrates whichincrust and impregnate the cell walls and interstices, as well as the hollow inside of the tube of a raw or untreated cellulose fiber, and which by their presence greatly reduce its non-conductivity. By this treatment each hollow cylindrical fiber of the flax becomes an air-cell infinitely small; but the innumerable aircells thus present in a mass of this fiber makes it a most perfect non-conductor of heat and cold.

Having thus fully described my invention,

heated surfaces, or for refrigerator-surfaces, or the like, consisting of a mixture of degummed and delignated cellulose fiber of flax combined with a filler of partially-disintegrated vegetable tissue,substantially as specified.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

GEORGE KELLY.

Witnesses:

PHIL ALLEN, J 1., FRANK E. HANSOOM. 

